Hydrosphere: Energy from Water Overview

• The hydrosphere refers to all the water on the Earth’s surface, which includes oceans, lakes, rivers, and even underground water.
• Energy from water, also known as hydroelectric power, is a renewable energy source that harnesses the power of water to generate electricity.
• It’s among the most used renewable energy sources worldwide, primarily due to its low cost, sustainability, and minimal environmental impact.

Components of a Hydroelectric Power Plant

• The main components of a hydroelectric power plant are a dam, a reservoir, a penstock, a turbine, and a generator.
• A dam is constructed across a river to create a reservoir, which stores water.
• Water from the reservoir flows down the penstock due to gravity, which directs the water to the turbine.
• The intense pressure of the water spins the turbine, which is connected to the generator.
• The motion of the turbine spins a magnet inside the generator that produces electricity.

Different Types of Hydroelectric Power Systems

• There are three main types of hydroelectric systems: impoundment, diversion, and pumped storage.
• Impoundment is the most common type and uses a dam to store water in a reservoir.
• Diversion, or run-of-river, channels a portion of the river's flow through a canal or penstock.
• Pumped storage stores energy by using two water reservoirs at different levels and can be used to supply the grid with power during periods of high demand.

Advantages of Hydroelectric Power

• Hydroelectric power is a renewable energy source, meaning it uses a resource - water - that is constantly replenished by nature.
• It produces no direct waste, which means it doesn’t contribute to greenhouse gas emissions.
• Hydroelectric power plants are capable of being scaled to meet energy demand, with the potential to generate large amounts of electricity.
• In addition to energy creation, reservoirs can also be used for water supply and irrigation purposes.

Disadvantages of Hydroelectric Power

• Dams can have a significant impact on local ecosystems by altering habitats and blocking migratory paths of aquatic organisms.
• The construction of a hydroelectric dam is very costly, and it can also lead to displacement of people if residential areas are present in the area set to be flooded.
• While hydroelectric plants produce no direct waste, the creation of a reservoir can lead to indirect emissions, primarily through the decomposition of flooded plants and soil.

Sustainability of Hydroelectric Power

• Hydroelectric power is a sustainable energy solution as the water cycle is an endless, renewable process.
• Despite the potential negative impacts, including harm to local habitats and potential displacement of communities due to dam construction, mitigating strategies can be implemented.
• These strategies include fish ladders to allow aquatic organisms to migrate, reservoir management to minimize greenhouse gas emissions, and appropriate site selection to minimize displacement and habitat loss.